JP2007168692A - Braking/driving force control device for vehicle provided with torque converter in drive system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress creep torque to a proper degree while preventing an occupant of a vehicle from feeling odd by considering braking/driving operation status of a driver and a traveling status of the vehicle when braking force for suppressing the creep torque is increased/reduced. <P>SOLUTION: When the execution condition of creep torque suppression control is materialized (S50, 90), basic target braking force Fctb for suppressing the creep torque is operated (S100), a target increase/reduction amount ΔFct of creep torque suppression braking force at starting and finishing of creep torque suppression control is operated according to the fact whether or not the vehicle is in the stopping state, a variation ratio of a braking requirement amount, a variation ratio of an acceleration requirement amount and a friction coefficient μ of a road surface (S110, 170), and the creep torque suppression braking force given to the wheel is controlled such that the increase/reduction amount of the creep torque suppression braking force at starting and finishing of creep torque suppression control becomes the target increase/reduction amount ΔFct (S130-250). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a braking / driving force control device for a vehicle having a torque converter in a driving system, and more particularly to a braking / driving force control device that suppresses and controls creep torque.

As one of the braking / driving force control devices for vehicles such as automobiles, when a vehicle having a torque converter in a drive system is driven by creep torque, as described in Patent Document 1, for example, a proportional valve is used. There is already known a braking / driving force control device configured to change the hydraulic pressure corresponding to the break point to the high pressure side by the amount corresponding to the creep torque.
Japanese Patent Laid-Open No. 8-108836

  In vehicles equipped with a torque converter in the drive system, the hydraulic pressure corresponding to the valve break point of the proportional valve is not changed to the high pressure side by the amount of creep torque, but excessive creep torque is automatically prevented. Therefore, it is conceivable to automatically apply a braking force for suppressing the creep torque to the wheels.

  However, since the creep torque increases and fluctuates during idle-up control associated with engine cold start and air conditioner auxiliary operation, the braking force to suppress creep torque (creep torque suppression braking force) is also controlled by idle-up control. It fluctuates as it gets higher. For this reason, when the creep torque suppression braking force is automatically applied to the wheel, the braking force applied to the wheel fluctuates in a different manner from the driver's braking / driving intention and braking / driving operation. The driver may feel uncomfortable.

  For example, when the creep torque suppression braking force is increased in a situation where the driver's braking operation amount is constant, the driver feels that the vehicle has become unnaturally heavy. In addition, in a situation where the driver is accelerating and starting the vehicle, if the creep torque suppressing braking force remains excessively, the driver feels caught. In addition, when the driver tries to start the vehicle on a road with a low coefficient of friction on the road surface, if the creep torque suppression braking force is suddenly reduced, the driving force of the wheels will rise rapidly. As a result, wheel spin occurs, making it difficult to start the vehicle well.

  Furthermore, from the viewpoint of ensuring the durability of the brake pad and reducing brake noise and noise, it is preferable that the creep torque suppression braking force be reduced as quickly as possible at the end of the creep torque suppression control. However, if the creep torque suppression braking force is suddenly reduced in a situation where the vehicle is traveling, the deceleration of the vehicle is abruptly reduced, and the vehicle occupant feels uncomfortable with the vehicle speed change behavior.

  The present invention has been made in view of the above-described problems in a conventional braking / driving force control device configured to suppress creep torque by applying creep torque suppressing braking force to a wheel. The main problem is to consider the driver's braking / driving operation status and vehicle running status when increasing or decreasing the braking force to suppress the creep torque, while preventing the vehicle occupant from feeling uncomfortable. It is to properly suppress the creep torque.

  According to the present invention, the main problem described above is applied to a vehicle having a torque converter in the drive system, and the braking force applied to the wheels so as to obtain a target braking force according to a driver or a braking request for automatic control. The braking force control means for controlling the engine and the driving force applied to the wheels by controlling the output of the engine in response to a driver or automatic control driving request, and when the idle-up condition is satisfied, the engine idle rotation Engine control means for performing idle-up control for increasing the number, and the braking force control means increases and changes the target braking force so that at least the braking force of the drive wheels is increased when the idle-up control is being performed. In the braking / driving force control device for a vehicle, the braking force control means reduces the magnitude of the rate of change of the increase change amount of the target braking force to an allowable limit value or less. And the allowable limit value is increased when the change rate of the braking / driving request amount for the driver or automatic control is large compared to when the change rate of the braking / driving request amount is small. The vehicle braking / driving force control device (structure of claim 1), which is applied to a vehicle having a torque converter in a drive system, is applied to a wheel so as to achieve a target braking force according to a driver or a braking request of automatic control. The braking force control means for controlling the applied braking force, and the driving force applied to the wheels by controlling the engine output in response to the driver or automatic control driving request, and the idle up condition is established Engine control means for performing idle-up control for increasing the idle speed of the engine, and the braking force control means is operated when the idle-up control is performed. In the vehicle braking / driving force control device for increasing and changing the target braking force so that at least the braking force of the driving wheel is increased, the braking force control means has a rate of change of the increase change amount of the target braking force. In the vehicle braking / driving force control device (configuration of claim 3), wherein the allowable limit value is made larger when the vehicle speed is low than when the vehicle speed is high. Applied to a vehicle having a torque converter in the system, and a braking force control means for controlling a braking force applied to a wheel so as to obtain a target braking force according to a driver or a braking request for automatic control, and a driver or automatic control The engine output is controlled in response to the drive request of the engine to control the driving force applied to the wheels, and when the idle-up condition is satisfied, the idle engine increases the engine idle speed. Engine control means for controlling the vehicle, and when the idle-up control is being performed, the braking force control means increases or changes the target braking force so that at least the braking force of the driving wheel increases. In the force control device, the braking force control means restricts the rate of change of the increase change amount of the target braking force to an allowable limit value or less, and when the road surface friction coefficient is low, the road surface friction coefficient is high. This is achieved by a vehicle braking / driving force control device (structure of claim 5) characterized in that the allowable limit value is made smaller than that.

  According to the present invention, in order to effectively achieve the above main problem, in the configuration of claim 1, the braking force control means has a larger change rate of the braking / driving request amount. The allowable limit value is configured to be variably set according to the change rate of the braking / driving request amount so that the allowable limit value is increased (configuration of claim 2).

  According to the present invention, in order to effectively achieve the main problems described above, in the configuration of claim 3, the braking force control means can be used when the vehicle is running when the vehicle is stopped. The permissible limit value is configured to be larger than the above (the configuration of claim 4).

  According to the present invention, in order to effectively achieve the main problems described above, in the configurations of claims 1 to 5, the braking force control means is configured such that the allowable limit value increases as the road surface friction coefficient decreases. The allowable limit value is variably set in accordance with the friction coefficient of the road surface so as to be reduced (structure of claim 6).

  According to the present invention, in order to effectively achieve the main problems described above, in the configuration of the above-mentioned claims 1 to 6, the braking force control means is subjected to the idle-up control and the driver. Alternatively, the target braking force is configured to be increased and changed only when there is an automatic control braking request (configuration of claim 7).

  According to the configuration of the first aspect, the rate of change in the increase change amount of the target braking force is limited to the allowable limit value or less, and the rate of change in the driver / automatic control braking / driving request amount is large. When the change rate of the braking / driving operation amount is small, the allowable limit value is increased as compared with the case where the change rate of the braking / driving operation amount is small. Compared to when the magnitude is large, the magnitude of change in the target brake force increase change amount is reduced, and when the magnitude of change in the braking / driving request quantity is large, the magnitude of change in the braking / driving demand quantity is small It is possible to tolerate a large change in the amount of change in the target braking force as compared to the case. Therefore, the creep torque suppression braking force can be adjusted according to the magnitude of the change rate of the driver or automatic control braking / driving request amount. Change the degree of change, While preventing the feel occupant discomfort of the vehicle changes in creep torque suppression braking force due to largely different from the occupant of the braking-driving intention of the vehicle by Les, it is possible to properly suppress the creep torque.

  According to the configuration of claim 2, the allowable limit value is variable according to the magnitude of the change rate of the braking / driving request amount so that the allowable limit value increases as the change rate of the braking / driving request amount increases. Because it is set, the degree of change in creep torque suppression braking force can be optimized according to the change rate of the driver or automatic control braking / driving request amount, which makes the vehicle occupant feel uncomfortable It is possible to more appropriately suppress the creep torque while preventing the occurrence of noise more reliably.

  According to the third aspect of the present invention, the rate of change of the increase change amount of the target braking force is limited to the allowable limit value or less, and the allowable limit value is lower when the vehicle speed is low than when the vehicle speed is high. Therefore, when the vehicle speed is high, the creep torque suppression braking force can be prevented from changing greatly, and the vehicle occupant can be prevented from feeling uncomfortable due to the large change in braking force. When the braking force is low and there is a low possibility that the vehicle occupant feels uncomfortable, the creep torque suppression braking force is allowed to change greatly, and the creep torque is effectively suppressed, and the creep torque suppression control is quickly performed. Can be terminated.

  According to the fourth aspect of the present invention, when the vehicle is stopped, the allowable limit value is increased as compared with when the vehicle is running. Therefore, the vehicle is stopped and the braking force is greatly changed. However, when there is no fear that the vehicle occupant feels uncomfortable, the creep torque suppression braking force is allowed to change greatly, and the creep torque is effectively and reliably suppressed, and the creep torque suppression control is immediately terminated. Can do.

  According to the fifth aspect of the present invention, when the rate of change of the increase change amount of the target braking force is limited to the allowable limit value or less, and when the road surface friction coefficient is low, the road surface friction coefficient is high. Since the allowable limit value is made smaller than this, when the road surface friction coefficient is low, it is caused by a sharp increase in the wheel spin and creep torque suppression braking force due to the rapid decrease in creep torque suppression braking force. Excessive braking slip can be prevented, and when the road friction coefficient is high, creep torque suppression braking force is allowed to change greatly, creep torque is effectively suppressed, and creep torque suppression control is terminated quickly. Can do.

  Further, according to the configuration of the sixth aspect, the allowable limit value is variably set according to the friction coefficient of the road surface so that the allowable limit value becomes smaller as the friction coefficient of the road surface becomes lower. The degree of change in the creep torque suppression braking force can be optimized, whereby the creep torque can be more appropriately suppressed while more reliably preventing wheel spin and excessive braking slip.

  According to the seventh aspect of the present invention, since the target braking force is increased and changed only when the idle up control is performed and the driver or the automatic control braking request is issued, the idle up control is executed. Ensure that the braking force of the entire vehicle is unnecessarily increased in situations where there is no driver or no automatic control braking requirement and that the driver's acceleration demands are not met due to this. can do.

[Preferred embodiment of problem solving means]
According to one preferred aspect of the present invention, in the configuration of claim 1, the braking force control means increases the rate of change of the driver or automatic control required braking amount in the process of increasing the target braking force. When the magnitude of the brake is large, the permissible limit value is increased compared to when the increase rate of change in the required braking amount is small, and when the decrease rate of change in the required braking amount of the driver or the automatic control is large, braking is performed. The allowable limit value is configured to be smaller than that when the reduction rate of the required amount is small (preferred aspect 1).

  According to another preferred embodiment of the present invention, in the configuration of claim 1, the braking force control means increases the required braking amount for the driver or automatic control in the process of reducing the target braking force. When the rate of change is large, the allowable limit value is made smaller than when the rate of increase in braking requirement is small, and the rate of decrease in rate of braking required by the driver or automatic control is large. In some cases, the allowable limit value is set to be larger than when the rate of decrease in the braking request amount is small (preferred aspect 2).

  According to another preferred embodiment of the present invention, in the configuration of claim 1, the braking force control means increases the required driving amount of the driver or the automatic control in the process of reducing the target braking force. When the rate of change is large, the permissible limit value is increased compared to when the rate of increase in drive requirement is small, and the rate of decrease in rate of change in drive requirement for the driver or automatic control is large. In some cases, the allowable limit value is set to be smaller than that in the case where the decrease rate of change in the requested drive amount is small (Preferable Mode 3).

  According to another preferred embodiment of the present invention, in the configuration of the above-mentioned claim 2 or the above-mentioned preferred embodiment 1, the braking force control means controls the driver or the automatic control in the process of increasing the target braking force. The allowable limit value increases as the increase rate of change in the required braking amount increases, and the allowable limit value decreases as the decrease rate of decrease in the required braking amount of the driver or automatic control decreases. The allowable limit value is variably set according to the magnitude of the change rate of the braking request amount for automatic control (preferred aspect 4).

  According to another preferred aspect of the present invention, in the configuration of the above-mentioned claim 2 or the preferred aspect 2, the braking force control means is configured to control the driver or the automatic control in the process of reducing the target braking force. The allowable limit value decreases as the increase rate of change in the required braking amount increases, and the allowable limit value increases as the decrease rate of decrease in the required braking amount for the driver or automatic control increases. The allowable limit value is variably set according to the magnitude of the change rate of the braking request amount for automatic control (preferred aspect 5).

  According to another preferred embodiment of the present invention, in the configuration of the above-mentioned claim 2 or the above-mentioned preferred embodiment 3, the braking force control means controls the driver or the automatic control in the process of reducing the target braking force. The allowable limit value increases as the increase change rate of the drive request amount increases, and the allowable limit value decreases as the decrease change rate of the drive request amount of the driver or automatic control increases. The allowable limit value is variably set in accordance with the change rate of the drive request amount for automatic control (preferred aspect 6).

  According to another preferred embodiment of the present invention, in the construction of claim 5, the braking force control means is configured as described in claim 1 when the road surface friction coefficient is low compared to when the road surface friction coefficient is high. To 4 or the above-described preferred modes 1 to 6 are configured to reduce the allowable limit value (preferred mode 7).

  According to another preferred embodiment of the present invention, in the configuration of the above-mentioned claim 6 or the above-mentioned preferred embodiment 7, the braking force control means has the above-described claims 1 to 4 or the above-mentioned preferred embodiment as the road surface friction coefficient is lower. The allowable limit value is variably set according to the friction coefficient of the road surface so that the allowable limit values of 1 to 6 are reduced (preferred aspect 8).

  According to another preferred embodiment of the present invention, in the configuration of the above-mentioned claim 7 or the preferred embodiments 1 to 8, the braking force control means is “the idle-up control is performed and the driver or the automatic braking is performed. The vehicle is in a situation where there is a control braking request and the vehicle is in a stopped state "and" the idle up control is being performed and there is a driver or braking request for automatic braking control and the road surface friction coefficient is below a reference value. The target braking force is configured to be increased and changed only when any one of the creep torque suppression control execution conditions “is in a traveling state” is satisfied (preferred aspect 9).

  According to another preferred aspect of the present invention, in the configuration of the above-described claims 1 to 7 or the preferred aspects 1 to 9, the braking force control means does not perform the actual driving force and idle-up control of the vehicle. The change amount of the target braking force is calculated on the basis of the deviation from the target driving force of the vehicle (preferred aspect 10).

  According to another preferred embodiment of the present invention, in the configuration of the above-mentioned claims 1 to 7 or the preferred embodiments 1 to 10, the vehicle has a drive wheel and a driven wheel, and the braking force control means is the drive wheel. The target braking force is increased and changed, and the target braking force of the driven wheel is reduced and changed (preferred aspect 11).

  According to another preferred aspect of the present invention, in the configuration of the preferred aspect 11, the increase change amount of the target braking force of the drive wheel is larger than the reduction change amount of the target braking force of the driven wheel. Constructed (preferred aspect 12).

  According to another preferred aspect of the present invention, in the configuration of the preferred aspect 11 or 12, the reduction change amount of the target braking force of the driven wheel is smaller when the vehicle speed is low than when the vehicle speed is high. Constructed (preferred embodiment 13).

  According to another preferred embodiment of the present invention, in the configuration of the above-mentioned claims 1 to 7 or the preferred embodiments 1 to 13, the vehicle is configured to be a rear wheel drive vehicle (preferred embodiment 14).

  The present invention will now be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram (A) and a control system block diagram (B) showing one embodiment of a vehicle braking / driving force control device according to the present invention applied to a rear wheel drive vehicle.

  In FIG. 1, reference numeral 10 denotes an engine, and the driving force of the engine 10 is transmitted to a propeller shaft 18 via an automatic transmission 16 including a torque converter 12 and a transmission 14. The driving force of the propeller shaft 18 is transmitted to the left rear wheel axle 22L and the right rear wheel axle 22R by the differential 20, whereby the left and right rear wheels 24RL and 24RR which are driving wheels are rotationally driven.

  On the other hand, the left and right front wheels 24FL and 24FR are both driven wheels and steering wheels, and are not shown in FIG. 1, but are rack-and-pinion power that is driven in response to steering of the steering wheel by the driver. The steering device is steered in a known manner via a tie rod.

  The amount of intake air to the engine 10 is controlled by a throttle valve 28 provided in the intake passage 26, and the throttle valve 28 is driven by a throttle actuator 30 including an electric motor. The opening degree of the throttle valve 28 is controlled by the engine control device 34 via the throttle actuator 30 according to the depression amount of the accelerator pedal 33 detected by the accelerator opening degree sensor 32. In addition, an injector 36 for injecting fuel such as gasoline is provided at the supply port of each cylinder of the intake passage 26 of the engine 10, and the fuel injection amount by the injector 36 is also controlled by the engine control device 34.

  A signal indicating the amount of depression of the accelerator pedal 38 (accelerator opening A) is input from the accelerator opening sensor 32 to the engine control device 34, and the engine speed Ne and other signals from other sensors not shown in the figure. A signal indicating engine control information is input. The engine control unit 34 normally calculates the target engine torque Tet based on the accelerator opening A and the like, calculates the target opening φst of the throttle valve 28 based on the target engine torque Tet and the engine speed Ne, and opens the throttle valve 28. The degree is controlled to be the target opening φst.

  Further, the engine control device 34 performs idle-up control for increasing the number of revolutions of the idle operation of the engine 10 when a preset idle-up condition is satisfied, such as an idle operation at the time of cold start or an auxiliary machine operation.

  The braking force of the left and right front wheels 24FL, 24FR and the left and right rear wheels 24RL, 24RR is controlled by controlling the braking pressures of the corresponding wheel cylinders 46FL, 46FR, 46RL, 46RR by the hydraulic circuit 44 of the braking device 42. Although not shown in FIG. 1, the hydraulic circuit 44 includes a reservoir, an oil pump, various valve devices, and the like, and the braking pressure of each wheel cylinder is normally driven in accordance with the depression operation of the brake pedal 48 by the driver. Is controlled by the braking force control device 52 based on the pressure in the master cylinder 50, that is, the master cylinder pressure Pm.

  The braking pressure of each wheel cylinder is controlled regardless of the master cylinder pressure Pm so that the inter-vehicle distance is controlled to a value within a predetermined range when the inter-vehicle distance from the preceding vehicle is below a reference value. 52. Further, the braking pressure of each wheel cylinder is controlled by the braking force control device 52 regardless of the master cylinder pressure Pm in order to stabilize the behavior of the vehicle when the behavior of the vehicle deteriorates.

  As shown in FIG. 1B, the braking force control device 52 includes a signal indicating an inter-vehicle distance L between a preceding vehicle ahead of the vehicle and an obstacle detection sensor such as a CCD camera. A signal indicating the presence or absence of an obstacle in front of the vehicle is input from 56. The braking force control device 52 includes a signal indicating the steering angle θ from the steering angle sensor 58, a signal indicating the vehicle speed V from the vehicle speed sensor 60, a signal indicating the yaw rate γ of the vehicle from the yaw rate sensor 62, and a road surface friction from the μ sensor 64. A signal indicating the coefficient μ, a signal indicating the master cylinder pressure Pm from the pressure sensor 66, and a signal indicating the pressure Pi (i = fl, fr, rl, rr) in the wheel cylinders 46FL to 46RR are input from the pressure sensors 70FL to 70RR, respectively. Is done. The braking force control device 52 executes a signal indicating the accelerator opening A, a signal indicating the target output torque Tet of the engine 10, a signal indicating the actual output torque Tea of the engine 10, and idle-up control from the engine control device 34. A signal indicating whether or not there is also input.

  The engine control device 34 and the braking force control device 52 actually include a CPU, a ROM, a RAM, an input / output port device, etc., which are connected to each other via a bidirectional common bus. And a drive circuit. The steering angle sensor 54 and the yaw rate sensor 58 detect the steering angle θ and the yaw rate γ of the vehicle, respectively, when the vehicle is turning left.

  Particularly in the illustrated embodiment, the braking force control device 52 determines whether the vehicle is in a stopped state at the start of creep torque suppression control according to the flowcharts shown in FIGS. Controls the rate of increase in creep torque suppression braking force according to the rate of change in the required braking amount of the control and the friction coefficient μ of the road surface, and at the end of creep torque suppression control, whether the vehicle is in a stopped state, Controls the rate of change in the required braking force for automatic control, the rate of change in the requested acceleration for driver or automatic control, and the rate of change in the creep torque suppression braking force according to the friction coefficient μ of the road surface. The rate of change of the braking torque suppression braking force at the start of the vehicle and at the end of the creep torque suppression control is determined by the driver's braking / driving operation status and vehicle driving status (vehicle speed and road surface friction Optimized according to).

  In the illustrated embodiment, the braking force control device 52 (1) “Idle-up control is performed and braking by the driver or automatic braking control is performed according to the flowcharts shown in FIGS. 2 to 4. There is a request and the vehicle is in a stopped state ”and (2)“ the vehicle is in a situation where the idle-up control is being performed and there is a driver or a braking request for automatic braking control and the friction coefficient of the road surface is below a reference value. It is determined whether or not any of the conditions “is in a traveling state” is satisfied, and when neither of the above conditions (1) and (2) is satisfied, the driver or a braking request for automatic braking control is performed. The braking force of each wheel is controlled so as to be a target braking force based on the above, thereby preventing unnecessary creep torque suppressing braking force from being applied to the wheel.

  On the other hand, when either of the above conditions (1) and (2) is established, the braking force control device 52 increases the braking force of the left and right front wheels and decreases the braking force of the left and right rear wheels. The target braking force based on the braking request is changed so as to increase the braking force of the entire vehicle, and the braking force of each wheel is controlled so as to be the target braking force after the change, so that the excess creep torque accompanying the idle-up control Is surely suppressed.

  Next, a braking force control routine in the illustrated embodiment will be described with reference to the flowchart shown in FIG. The control according to the flowchart shown in FIG. 2 is started by closing an ignition switch not shown in the figure, and is repeatedly executed at predetermined time intervals. In FIG. 2, the flag Fb relates to whether or not the target braking force is changed due to the idle-up control. 1 means that the target braking force is changed. Fb is initialized to 0 at the start of control.

  First, in step 10, a signal indicating the master cylinder pressure Pm is read. In step 20, the vehicle distance control and behavior control are not required. When the target braking force Fv and the target yaw moment Mv (V = 0) are calculated and the automatic control of the braking / driving force by the inter-vehicle distance control or the behavior control is necessary, the inter-vehicle distance is performed in a manner known in the art. A vehicle target braking force Fv and a target yaw moment Mv for achieving control or behavior control are calculated.

  In step 30, the wheels are provisional for achieving the vehicle target braking force Fv and the target yaw moment Mv in a manner known in the art based on the vehicle target braking force Fv and the target yaw moment Mv. A target braking force Fwtpi (i = fl, fr, rl, rr) is calculated.

  In step 40, it is determined whether or not the flag Fb is 1, that is, whether or not creep torque suppression control accompanying idle-up control is being performed. If an affirmative determination is made, step 90 is performed. When a negative determination is made, the process proceeds to step 50.

  In step 50, it is determined whether or not the creep torque suppression control start condition is satisfied according to the routine shown in the flowchart of FIG. 3, and if an affirmative determination is made, the flag Fb is determined in step 70. Is set to 1 and the previous value Fctf of the creep torque suppression target braking force Fct is set to 0, the process proceeds to step 100. If a negative determination is made, the target braking force Fwti of each wheel is determined in step 80. The provisional target braking force Fwtpi corresponding to each is set, and then the routine proceeds to step 250.

  In step 90, as in step 50, it is determined whether or not the end condition of the creep torque suppression control is satisfied according to the routine according to the flowchart shown in FIG. Proceed to step 100, and if an affirmative determination is made, proceed to step 170.

  In step 100, the deviation between the actual output torque Tea of the engine input from the engine control device 34 and the target output torque Tet of the engine that is optimum when the idle-up control is not performed, and the shift stage of the automatic transmission 16 Based on this information, an excessive driving force ΔFe of the vehicle by idle-up control is calculated, and a creep torque suppression basic target braking force Fctb is calculated based on the excessive driving force ΔFe.

  In step 110, the target increase / decrease amount ΔFct of the creep torque suppression target braking force is calculated in accordance with the routine shown in the flowchart of FIG. 5, and in step 130, the previous value Fctf of the creep torque suppression target braking force Fct and the step are calculated. The creep torque suppression target braking force Fct is calculated as the sum of the target increase / decrease amount ΔFct calculated at 110.

  In step 140, it is determined whether or not the process of gradually increasing the creep torque suppression target braking force Fct is completed by determining whether or not the creep torque suppression target braking force Fct is greater than or equal to the creep torque suppression basic target braking force Fctb. When a negative determination is made, the routine proceeds to step 160. When an affirmative determination is made, the creep torque suppression target braking force Fct is set to the creep torque suppression basic target braking force Fctb in step 150, and thereafter Proceed to step 160.

  In step 160, the correction coefficient Kvb is calculated from the map corresponding to the graph shown in FIG. 11 based on the vehicle speed V so that the correction coefficient Kvb is smaller than 1 and less than 1 as the vehicle speed V is lower. Is done.

  In step 170, the target increase / decrease amount ΔFct of the creep torque suppression target braking force is calculated according to the routine according to the flowchart shown in FIG. 6, and in step 200, the step value is calculated from the previous value Fctf of the creep torque suppression target braking force Fct. The creep torque suppression target braking force Fct is calculated as a value obtained by subtracting the target increase / decrease amount ΔFct calculated in 200.

  In step 210, it is determined whether or not the creep torque suppression target braking force Fct has been gradually reduced by determining whether or not the creep torque suppression target braking force Fct is 0 or less. If YES, the routine proceeds to step 230. If an affirmative determination is made, the flag Fb is reset to 0 in step 220 and the creep torque suppression target braking force Fct is set to 0. Thereafter, the routine proceeds to step 230. .

  In step 230, the target braking forces Fwtfl and Fwtfr for the left and right front wheels are calculated according to the following equations 1 and 2, respectively, and in step 240, the target braking forces Fwtrl and Fwtrr for the left and right rear wheels are calculated as In step 250, the braking force of each wheel is controlled to become the target braking force Fwti.

Fwtfl = Fwtpfl−KvbFct / 2 (1)
Fwtfr = Fwtpfr-KvbFct / 2 (2)
Fwtrl = Fwtprl + Fct / 2 (3)
Fwtfr = Fwtprr + Fct / 2 (4)

  Next, the routine for determining whether or not the start condition of the creep torque suppression control executed in step 50 is satisfied will be described with reference to the flowchart shown in FIG.

  First, in step 52, it is determined whether or not the idle-up control is being performed for the engine 10. If a negative determination is made, the process proceeds to step 68. If an affirmative determination is made, the process proceeds to step 54.

  In step 54, it is determined whether or not there is a braking request by the driver or a braking request by automatic braking control such as inter-vehicle distance control or behavior control. If a negative determination is made, the process proceeds to step 68, where affirmative When the determination is made, the process proceeds to step 56.

  In step 56, it is determined whether or not the shift position of the automatic transmission 16 is in the forward gear or the reverse gear (vehicle running gear) based on a signal from a shift position sensor not shown in the drawing. If a negative determination is made, the process proceeds to step 68. If an affirmative determination is made, the process proceeds to step 58.

  In step 58, it is determined whether or not there is an acceleration request by the driver or an acceleration request by automatic control such as inter-vehicle distance control or behavior control. If a negative determination is made, the process proceeds to step 68, where an affirmative determination is made. When the operation is performed, the process proceeds to step 60.

  In step 60, it is determined whether or not the vehicle speed V is equal to or less than a reference value Vo (positive constant). If a negative determination is made, the process proceeds to step 68. If an affirmative determination is made, step 62 is performed. Proceed to

  In step 62, it is determined whether or not the friction coefficient μ of the road surface is equal to or smaller than a reference value μo (positive constant). If a negative determination is made, the process proceeds to step 68, where an affirmative determination is made. Sometimes go to step 64.

  In step 64, it is determined whether or not the vehicle speed V is 0, that is, whether or not the vehicle is in a stopped state. If a negative determination is made, the creep torque suppression control is performed in step 68. After the determination that the starting condition is satisfied, the routine proceeds to step 70. When the determination is affirmative, in step 66, it is determined that the starting condition for creep torque suppression control is not satisfied. Then, go to step 80. If each wheel is provided with a wheel speed sensor, whether the vehicle speed V is 0 is determined by determining that the vehicle speed V is 0 when the wheel speeds of the left and right front wheels that are driven wheels are 0. It may be determined.

  Note that steps 92 to 108 in FIG. 4 correspond to steps 52 to 68 in FIG. 3, respectively, and accordingly, a routine for determining whether or not the end condition of the creep torque suppression control executed in step 90 is satisfied. Is also executed in the same manner as the routine for determining whether or not the creep torque suppression control start condition is satisfied. In step 106, it is determined that the creep torque suppression control end condition is not satisfied. The process proceeds to step 100, and in step 108, after it is determined that the end condition of the creep torque suppression control is satisfied, the process proceeds to step 170.

  Next, the target increase / decrease amount ΔFct calculation routine of the creep torque suppression target braking force executed in step 110 will be described with reference to the flowchart shown in FIG.

  First, in step 112, it is determined whether or not the vehicle speed V is 0, that is, whether or not the vehicle is in a stopped state. If a negative determination is made, the driver determines in step 114 that the vehicle speed V is zero. Creep torque suppression based on the map corresponding to the graph shown by the solid line in FIG. 7 based on the rate of change of the required braking amount or the rate of change of the required braking amount by automatic braking control (positive is an increasing rate of change, negative is a decreasing rate of change) When the basic limit increase amount ΔFab of the target braking force is calculated and an affirmative determination is made, in step 116, based on the rate of change of the braking request amount by the driver or the rate of change of the braking request amount by automatic braking control in FIG. The basic limit increase ΔFab of the creep torque suppression target braking force is calculated from the map corresponding to the graph indicated by the broken line.

  In step 118, the correction coefficient Km is calculated from the map corresponding to the graph shown in FIG. 10 on the basis of the road friction coefficient μ so that the correction coefficient Km decreases in the positive range as the road friction coefficient μ decreases. In step 120, the limit increase amount ΔFa for preventing the creep torque suppression target braking force Fct from increasing at an excessive increase rate is calculated as the product of the correction coefficient Km and the basic limit increase amount ΔFab. Is done.

  In step 122, it is determined whether or not the deviation between the creep torque suppression basic target braking force Fctb and the previous value Fctf of the creep torque suppression target braking force Fct is larger than the limit increase amount ΔFa, that is, the creep torque suppression braking force is determined. It is determined whether or not the creep torque suppression basic target braking force Fctb is not reached even if the limit increase amount ΔFa is increased. If an affirmative determination is made, in step 124, the target of the creep torque suppressing braking force is determined. When the increase / decrease amount ΔFct is set to the limit increase amount ΔFa and a negative determination is made, in step 126, the target increase / decrease amount ΔFct of the creep torque suppression braking force is set to the creep torque suppression target braking force from the creep torque suppression basic target braking force Fctb. It is set to a value obtained by subtracting the previous value Fctf of Fct.

  Next, the target increase / decrease amount ΔFct calculation routine of the creep torque suppression target braking force executed in step 170 will be described with reference to the flowchart shown in FIG.

  First, in step 172, it is determined whether or not the vehicle speed V is 0, that is, whether or not the vehicle is in a stopped state. If an affirmative determination is made, the process proceeds to step 180, and a negative determination is made. If yes, go to step 174.

  In step 174, it is determined whether or not there is a change rate of the acceleration request by the driver or an acceleration request by automatic braking control. If a negative determination is made, in step 176, the braking request amount by the driver is determined. The basic limit reduction amount ΔFbb of the creep torque suppression target braking force is calculated from the map corresponding to the graph shown by the solid line in FIG. When it is performed, in step 178, based on the change rate of the acceleration request amount by the driver or the change rate of the acceleration request amount by the automatic braking control (positive is an increase change rate, negative is a decrease change rate) in the solid line of FIG. The basic limit reduction amount ΔFbb of the creep torque suppression target braking force is calculated from the map corresponding to the graph shown.

  Similarly, at step 180, it is determined whether or not there is an acceleration request by the driver or an acceleration request by automatic braking control, and when a negative determination is made, at step 182 the braking request amount by the driver. The basic limit reduction amount ΔFbb of the creep torque suppression target braking force is calculated from the map corresponding to the graph shown by the broken line in FIG. When it is performed, in step 184, based on the change rate of the acceleration request amount by the driver or the change rate of the acceleration request amount by the automatic braking control, the creep torque suppression target is obtained from the map corresponding to the graph shown by the broken line in FIG. A basic limit reduction amount ΔFbb of the braking force is calculated.

  In step 186, the correction coefficient Km is calculated from the map corresponding to the graph shown in FIG. 10 on the basis of the road friction coefficient μ so that the correction coefficient Km decreases in the positive range as the road friction coefficient μ decreases. In step 188, the limit decrease amount ΔFb for preventing the creep torque suppression target braking force Fct from decreasing at an excessive decrease rate is calculated as the product of the correction coefficient Km and the basic limit decrease amount ΔFbb. Is done.

  In step 190, it is determined whether or not the deviation between the previous value Fctf of the creep torque suppression target braking force Fct and the limit decrease amount ΔFb is smaller than 0, that is, the creep torque suppression braking force is decreased by the limit decrease amount ΔFa. In step 192, the target increase / decrease amount ΔFct of the creep torque suppression braking force is reduced by a limit. When the amount ΔFb is set and a negative determination is made, in step 194, the target increase / decrease amount ΔFct of the creep torque suppression braking force is set to the previous value of the creep torque suppression target braking force Fct.

  Thus, according to the illustrated embodiment, the provisional target braking force Fwtpi of each wheel is calculated in steps 20 and 30 based on the driver or braking request for automatic braking, and the creep torque suppression control is performed in steps 50 and 90. It is determined whether or not the execution condition of the vehicle is satisfied. When the execution condition of the creep torque suppression control is satisfied, in steps 100 to 160 and steps 230 to 250, the excessive driving force of the vehicle by the idle-up control is determined. The creep torque suppression target braking force Fct is calculated based on ΔFe, and the target braking forces Fwtfl and Fwtfr for the left and right front wheels are reduced and changed based on the creep torque suppression target braking force Fct, and the target braking forces Fwtrl and Fwtrr for the left and right rear wheels. Is increased and the braking force of each wheel is controlled to become the target braking force Fwti after the change. Torque restriction control is executed.

  Therefore, according to the illustrated embodiment, when the execution condition of the creep torque suppression control is satisfied, that is, when the creep torque is excessive due to the idle up control, the excess driving force ΔFe of the vehicle by the idle up control is increased. Accordingly, the braking force of the entire vehicle is increased, and thereby the creep torque can be appropriately suppressed without being excessive or insufficient.

  Further, according to the illustrated embodiment, if it is determined in step 50 that the start condition of creep torque suppression control is satisfied, the creep torque suppression basic target braking force Fctb is calculated in step 100 and step 110 is executed. The target increase / decrease amount ΔFct of the creep torque suppression target braking force is calculated in step 130, and the sum of the previous value Fctf of the creep torque suppression target braking force Fct in step 130 and the target increase / decrease amount ΔFct calculated in step 110 is calculated. The creep torque suppression target braking force Fct is calculated, whereby the increase rate of the creep torque suppression target braking force Fct at the start of the creep torque suppression control is limited to the increase rate corresponding to the target increase / decrease amount ΔFct.

  In particular, the target increase / decrease amount ΔFct (target increase amount) at the start of the creep torque suppression control is calculated by steps 112 to 126 of the routine shown in FIG. 5, and as shown in FIG. It is variably set according to the rate of change in the required braking amount so that it increases as the rate of change increases and decreases as the rate of change in the required braking amount decreases.

  Therefore, in a situation where the braking operation amount of the driver at the start of the creep torque suppression control is constant, the creep torque suppression braking force is prevented from increasing suddenly, which makes the vehicle unnatural. It can be effectively prevented that the user feels heavier. In addition, when the amount of braking operation by the driver is increased at the start of creep torque suppression control, the creep torque suppression braking force can be increased quickly to exert the creep torque suppression effect at an early stage. When the amount of braking operation of the driver is reduced at the start of the suppression control, the creep torque suppression braking force can be gently increased to prevent the creep torque suppression braking force from increasing rapidly.

  Further, as shown in FIG. 7, the target increase / decrease amount ΔFct at the start of the creep torque suppression control is larger when the vehicle is in the stopped state than when the vehicle is in the running state, so that the braking force increases rapidly. However, when the vehicle is in a stopped state where the vehicle occupant does not feel uncomfortable, the creep torque suppression effect can be exerted quickly, and when the vehicle is in the running state, the increase in braking force is moderated and the braking force is reduced. It is possible to effectively prevent the occupant of the vehicle from feeling uncomfortable due to the rapid increase of.

  Further, the target increase / decrease amount ΔFct (target reduction amount) at the end of the creep torque suppression control is calculated by steps 172 to 194 of the routine shown in FIG. 6, and when there is no acceleration request for the driver or automatic control, FIG. As shown in FIG. 5, the braking request amount is variably set so as to decrease as the braking request amount increases and decreases as the braking request amount decreases.

  Therefore, when the braking operation amount of the driver is increased at the end of the creep torque suppression control, the creep torque suppression braking force can be gently decreased to prevent the creep torque suppression braking force from being rapidly decreased. Conversely, when the amount of braking operation by the driver is reduced at the end of the creep torque suppression control, the creep torque suppression braking force is quickly reduced so that the creep torque suppression braking force is applied to the wheel unnecessarily long. Can be prevented.

  Also, when the driver or the automatic control acceleration request is made at the end of the creep torque suppression control, the target increase / decrease amount ΔFct (target reduction amount) becomes larger as the increase rate of the acceleration request amount increases as shown in FIG. At the same time, it is variably set in accordance with the change rate of the acceleration request amount so as to decrease as the decrease change rate of the acceleration request amount increases.

  Therefore, when the acceleration operation amount of the driver is increased at the end of the creep torque suppression control, the creep torque suppression braking force is rapidly decreased to apply the creep torque suppression braking force to the wheels unnecessarily long. This effectively prevents the driver from feeling caught, and conversely when the amount of braking operation of the driver is reduced at the end of the creep torque suppression control, the creep torque suppression braking force is gently reduced. It can be prevented that the creep torque suppressing braking force is rapidly reduced.

  Also, as shown in FIGS. 8 and 9, the target increase / decrease amount ΔFct at the end of the creep torque suppression control is larger when the vehicle is stopped than when the vehicle is running, so that the braking force is suddenly increased. When the vehicle is stopped, creep torque suppression control can be immediately terminated when the vehicle is in a running state, and the braking force decrease can be moderated. Thus, it is possible to effectively prevent the vehicle occupant from feeling uncomfortable due to the sudden decrease in braking force.

  Further, according to the illustrated embodiment, when the vehicle is in a stopped state and when the vehicle is in a traveling state, the rate of change in the same braking request amount is seen and the creep torque suppression control is started. Since the target increase / decrease amount ΔFct at this time is smaller than the target increase / decrease amount ΔFct at the end of the creep torque suppression control, the increase rate of the creep torque suppression braking force at the start of the creep torque suppression control is determined at the end of the creep torque suppression control. The creep torque suppression braking force can be made smaller than the rate of decrease of the braking force in this manner, thereby reliably reducing the possibility that the vehicle occupant will feel uncomfortable due to the change in braking force at the start of creep torque suppression control. At the same time, the creep torque suppression braking force can be quickly reduced at the end of the creep torque suppression control.

  Further, according to the illustrated embodiment, in steps 118 and 186, the lower the road surface friction coefficient μ, the smaller the correction coefficient Km is calculated in a positive range. At the start of creep torque suppression control, step 120 is performed. The limit increase amount ΔFa is calculated as the product of the correction coefficient Km and the basic limit increase amount ΔFab. In steps 122 to 126, the target increase / decrease amount ΔFct is calculated based on the limit increase amount ΔFa, and the creep torque suppression control ends. Sometimes, in step 188, the limit decrease amount ΔFb is calculated as the product of the correction coefficient Km and the basic limit decrease amount ΔFbb, and in steps 190 to 194, the target increase / decrease amount ΔFct is calculated based on the limit decrease amount ΔFb.

  Therefore, at both the start of the creep torque suppression control and the end of the creep torque suppression control, the rate of change of the creep torque suppression braking force can be reduced as the friction coefficient μ of the road surface becomes lower. The increase / decrease change rate of the creep torque suppression braking force at the start of the suppression control and at the end of the creep torque suppression control can be optimized according to the friction coefficient μ of the road surface. For example, in a situation where the friction coefficient μ of the road surface is low, it is possible to reduce the possibility that the increase change rate of the creep torque suppression braking force at the start of the creep torque suppression control becomes excessive and the wheels are locked. At the end of creep torque suppression control, the decrease rate of creep torque suppression braking force can be reduced, reducing the possibility that the wheel will spin and the vehicle will be difficult to start, and the friction coefficient μ of the road surface will be reduced. In a high situation, it is possible to efficiently increase the creep torque suppression braking force at the start of the creep torque suppression control and reduce the creep torque suppression braking force at the end of the creep torque suppression control.

  In particular, according to the illustrated embodiment, it is determined in steps 50 and 90 whether or not the execution condition of the creep torque suppression control is satisfied, and as shown in FIGS. ) “Idle-up control is being executed (steps 52 and 92), and there is a braking request by the driver or a braking request by automatic braking control (steps 54 and 94), and the vehicle is in a stopped state (steps 64 and 104). And (2) “Idle-up control is being executed (steps 52 and 92) and there is a braking request by the driver or a braking request by automatic braking control (steps 54 and 94), and the friction coefficient of the road surface is below the reference value The creep torque suppression control is executed only when one of the conditions “the vehicle is in the running state (steps 62, 102)” is satisfied. Torque suppression control is performed unnecessarily, and creep torque suppression braking force can be prevented from being applied to the wheels unnecessarily, thereby reducing the possibility of occurrence of brake squeal and abnormal noise. The durability of the brake actuator can be improved and can also contribute to environmental protection.

  In particular, according to the illustrated embodiment, the above conditions (1) and (2) include the following: “The shift position of the automatic transmission is in the forward or reverse gear (steps 56 and 96) and the driver requests acceleration. Or, there is no acceleration request by automatic control (steps 58, 98) ", and therefore the creep torque suppression control is unnecessary as compared with the case where the above conditions (1) and (2) are satisfied. The possibility of being executed in a short time can be further reduced.

  Further, according to the illustrated embodiment, when the creep torque suppression control is executed, the braking force of the left and right rear wheels, which are driving wheels, is increased in steps 230 and 240 and the left and right front wheels, which are driven wheels, are increased. Since the braking force is reduced, the creep torque can be effectively suppressed while preventing the braking force of the entire vehicle from becoming excessive.

  Further, according to the illustrated embodiment, when the vehicle speed V is lower in step 160, the correction coefficient Kvb is calculated to be smaller in the range of greater than 0 and less than 1, and when the creep torque suppression control is executed. Since the amount of reduction of the braking force of the left and right front wheels is controlled to a value multiplied by the correction coefficient Kvb, the braking force of the left and right rear wheels, which are the driving wheels, is reliably increased and the driven wheels are used in a situation where the vehicle speed is low. The braking force of certain left and right front wheels can be reduced, and it is possible to reliably prevent the creep torque suppressing braking force from being applied unnecessarily in the medium to high speed vehicle speed range.

  Further, according to the illustrated embodiment, the change rate of the creep torque suppression braking force at the start of the creep torque suppression control is variably set according to the change rate of the braking request amount of the driver or the automatic control, and the creep torque suppression control is performed. Since the change rate of the creep torque suppression braking force at the end of the step is variably set according to the change rate of the acceleration request amount of the driver or automatic control, the change rate of the brake request amount of the driver and In addition to optimizing the rate of change of the braking force to suppress the creep torque according to the change rate of the driver's acceleration request amount, the automatic control braking can be performed even when the automatic control braking request amount or the acceleration request amount changes. The change rate of the creep torque suppression braking force can be optimized according to the change rate of the required amount and the change rate of the acceleration required amount of automatic control.

  Although the present invention has been described in detail with reference to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art.

  For example, in the above-described embodiment, the change rate of the creep torque suppression braking force at the start of the creep torque suppression control is variably set according to the change rate of the braking request amount of the driver or the automatic control. The change rate of the creep torque suppression braking force at the end of control is variably set according to the change rate of the acceleration request amount of the driver or automatic control, but the change rate of the creep torque suppression braking force is It may be modified so as to be variably set according to the change rate of the braking request amount and the acceleration request amount of the driver.

  Further, in the above-described embodiment, the rate of change of the creep torque suppression braking force at the start and end of the creep torque suppression control is determined in steps 112 and 172 as to whether or not the vehicle is stopped. Depending on whether the vehicle is in a stopped state or in a running state, the calculation is made from different maps (FIGS. 7 to 9). As shown in FIGS. You may correct | amend so that a map may be switched according to the vehicle speed V, without determining whether it exists in a stop state.

  In the above-described embodiments, the automatic control is the distance control and the braking / driving force control type behavior control. However, the automatic control controls the braking / driving force without depending on the driver's braking / driving operation. Any control known in the art may be used.

  In the above-described embodiment, the target braking force of the left and right rear wheels that are drive wheels is increased and changed, and the target braking force of the left and right front wheels that are driven wheels is reduced and changed. It may be modified so that the reduction of the target braking force of the driving wheel is not changed.

  Further, in the above-described embodiment, when the vehicle speed V is lower in step 160, the correction coefficient Kvb is calculated to be smaller in the range of greater than 0 and less than 1, and when the creep torque suppression control is executed. The amount of reduction in the braking force of the left and right front wheels is controlled to a value multiplied by the correction coefficient Kvb, but the correction coefficient Kvb may be omitted.

  Further, in the above embodiment, the vehicle is a rear wheel drive vehicle, but the vehicle to which the present invention is applied may be a front wheel drive vehicle or a four wheel drive vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram (A) and a control system block diagram (B) showing an embodiment of a vehicle braking / driving force control device according to the present invention applied to a rear wheel drive vehicle. It is a flowchart which shows the main routine of braking force control in an Example. FIG. 5 is a flowchart showing a subroutine for determining whether or not a start condition of creep torque suppression control in step 50 of FIG. 2 is satisfied. FIG. 3 is a flowchart showing a subroutine for determining whether or not an end condition for creep torque suppression control is satisfied in step 90 in FIG. 2. FIG. 3 is a flowchart showing a subroutine for calculating a target increase / decrease amount ΔFct of a creep torque suppression target braking force in step 110 of FIG. 2. 3 is a flowchart showing a subroutine for calculating a target increase / decrease amount ΔFct of a creep torque suppression target braking force in step 170 of FIG. 2. It is a graph which shows the relationship between the change rate of the braking request amount by a driver | operator, or the change rate of the braking request amount by automatic braking control, and basic restriction increase amount (DELTA) Fab of creep torque suppression target braking force. It is a graph which shows the relationship between the change rate of the braking request amount by a driver | operator, or the change rate of the braking request amount by automatic braking control, and basic restriction fall amount (DELTA) Fbb of creep torque suppression target braking force. It is a graph which shows the relationship between the change rate of the acceleration request amount by a driver | operator, or the change rate of the acceleration request amount by automatic control, and the basic restriction fall amount (DELTA) Fbb of creep torque suppression target braking force. It is a graph which shows the relationship between the friction coefficient (mu) of a road surface, and the correction coefficient Km. It is a graph which shows the relationship between the vehicle speed V and the correction coefficient Kvb. It is a graph which shows the relationship between the change rate of the braking request amount by a driver | operator, or the change rate of the braking request amount by automatic braking control, and the basic limit increase amount ΔFab of the vehicle speed V and the creep torque suppression target braking force. It is a graph which shows the relationship between the change rate of the braking request amount by a driver | operator, or the change rate of the braking request amount by automatic braking control, and the basic restriction fall amount (DELTA) Fbb of vehicle speed V and creep torque suppression target braking force. It is a graph which shows the relationship between the change rate of the acceleration request amount by a driver | operator, or the change rate of the acceleration request amount by automatic control, and the basic restriction fall amount (DELTA) Fbb of the vehicle speed V and creep torque suppression target braking force.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Engine 32 Accelerator opening sensor 34 Engine control apparatus 38 Accelerator pedal 42 Braking apparatus 52 Braking force control apparatus 54 Inter-vehicle distance sensor 56 Obstacle detection sensor 58 Steering angle sensor 60 Vehicle speed sensor 62 Yaw rate sensor 64 μ sensor 66 Pressure sensor 68FL-68RR Pressure sensor

Claims (7)

  A braking force control means that is applied to a vehicle having a torque converter in a drive system and controls a braking force applied to a wheel so as to obtain a target braking force according to a braking request of the driver or automatic control, and a driver or automatic Engine control means for controlling the driving force applied to the wheels by controlling the output of the engine in response to a drive request for control, and for performing idle-up control for increasing the engine idle speed when an idle-up condition is satisfied; In the vehicle braking / driving force control apparatus, the braking force control means increases and changes the target braking force so that at least the braking force of the driving wheel is increased when the idle-up control is performed. The braking force control means limits the magnitude of the change rate of the increase change amount of the target braking force to an allowable limit value or less, and also provides a driver or automatic control. The braking / driving force control for a vehicle is characterized in that the allowable limit value is increased when the rate of change in the required braking / driving amount is large compared to when the rate of change in the requested braking / driving amount is small. apparatus.   The braking force control means variably sets the allowable limit value according to the change rate of the braking / driving request amount so that the allowable limit value increases as the change rate of the braking / driving request amount increases. The braking / driving force control device for a vehicle according to claim 1.   A braking force control means that is applied to a vehicle having a torque converter in a drive system and controls a braking force applied to a wheel so as to obtain a target braking force according to a braking request of the driver or automatic control, and a driver or automatic Engine control means for controlling the driving force applied to the wheels by controlling the output of the engine in response to a drive request for control, and for performing idle-up control for increasing the engine idle speed when an idle-up condition is satisfied; In the vehicle braking / driving force control apparatus, the braking force control means increases and changes the target braking force so that at least the braking force of the driving wheel is increased when the idle-up control is performed. The braking force control means limits the magnitude of the change rate of the increase change amount of the target braking force to an allowable limit value or less, and when the vehicle speed is low, Vehicle braking driving force control apparatus characterized by greatly the allowable limit value than when high.   4. The vehicle braking / driving force control device according to claim 3, wherein the braking force control means increases the allowable limit value when the vehicle is stopped as compared with when the vehicle is running.   A braking force control means that is applied to a vehicle having a torque converter in a drive system and controls a braking force applied to a wheel so as to obtain a target braking force according to a braking request of the driver or automatic control, and a driver or automatic Engine control means for controlling the driving force applied to the wheels by controlling the output of the engine in response to a drive request for control, and for performing idle-up control for increasing the engine idle speed when an idle-up condition is satisfied; In the vehicle braking / driving force control apparatus, the braking force control means increases and changes the target braking force so that at least the braking force of the driving wheel is increased when the idle-up control is performed. The braking force control means limits the magnitude of the rate of change of the increase change amount of the target braking force to an allowable limit value or less and has a low road surface friction coefficient. Vehicle braking driving force control apparatus for can, characterized in that to reduce the allowable limit value compared to when the high friction coefficient of the road surface.   The said braking force control means variably sets the said permissible limit value according to the friction coefficient of a road surface so that the said permissible limit value may become so small that the friction coefficient of a road surface is low. Vehicle braking / driving force control device.   The said braking force control means increases and changes the said target braking force only when the said idle-up control is performed and there exists a driver | operator or the braking request | requirement of automatic control, The target braking force is changed. Vehicle braking / driving force control device.

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